Search: id:A102604 Results 1-1 of 1 results found. %I A102604 %S A102604 2,3,7,41,43,79,421 %N A102604 Numbers n such that ((2*n)^n-1)/(2*n-1) is prime. %C A102604 The next n in the sequence is > 4261 if exists %C A102604 Note that (b^n-1)/(b-1) is prime only if n is prime, so all the elements in this sequence must be primes. - Marco Bodrato (marco2007(AT)bodrato.it), Oct 31 2007 %e A102604 (((2*2)^2)-1)/(2*2-1) = 15/3 = 5 prime so a(1)=2 %Y A102604 Cf. A088790. %Y A102604 Sequence in context: A000317 A047024 A037843 this_sequence A119662 A163157 A000945 %Y A102604 Adjacent sequences: A102601 A102602 A102603 this_sequence A102605 A102606 A102607 %K A102604 more,nonn %O A102604 1,1 %A A102604 Pierre CAMI (pierrecami(AT)tele2.fr), Jan 29 2005 Search completed in 0.001 seconds